Anchoring device



Jan. 21, 1959 Filed Aug. 16,

M. B. CONRAD.

ANCHORING DEVICE Shee' of :5

INVENTOR. Amen/v 5. `60A/fem:

Jan. 21, 1969 M. B. CONRAD y ANCHORING DEVICE Sheet Filed Aug. 16,- 1965 INVENTOR MA1/Q7 /A/ KONRAD Jan. 2l, 1969 Filed Aug. 16, 1966 M. B. CONRAD ANCHORING DEVICE Sheet of 5 'rsf INVENTOIL A44/@77N 5. 60N/640 BY a M5L CQLL United States Patent O 3,422,897 ANCHRING DEVICE Martin B. Conrad, Carpinteria, Calif., assignor to Baker Oil Tools, Inc., City of Commerce, Calif., a corporation of California Filed Aug. 16, 1966, Ser. No. 572,826

U.S. Cl. 166-122 23 Claims Int. Cl. E21b i3/.126,33/127, 23/04 ABSTRACT F THE DISCLUSURE A retrievable bridge plug adapted to be anchored in a well bore, in which the anchor means comprises a body of discrete sand grains normally confined in an annular space between opposing packing elements movable one toward the other to set the plug in the well by causing outward movement of the sand grains into engagement with the well wall, the sand grains being confined between the packing elements. Such a plug in which a resilient sleeve is provided deiining the inner wall of the annular space, and iiuid pressure from below or from above the set packer acts on the resilient sleeve to force the sand grains into engagement with the well wall. Such a plug in which locking rings are provided to lock the plug in a set condition, and a shiftable retaining ring releasably holds the locking rings in locking engagement. Such a plug in which iiuid in the sand grain is allowed to pass from between the packing elements to prevent fluid lock during setting of the plug.

This invention pertains to an arrangement for retaining a body in a well and in particular to an improved construction for anchoring a plug, cement retainer, tubing string or the like.

Conventionally, anchors for use within a well casing provide their retaining force through the use of pressure elements that include teeth on their outer surfaces which are intended to become embedded in the wall of the casing and to withstand end loads in shear. It is necessary for the teeth to be sharp in order to dig into the well casing. Moreover, if the casing is particularly hard, it may be dicult or impossible to force the teeth properly into the surface of the casing. Also, the marks from the teeth in the well casing cause areas of stress concentration where corrosion can be encountered subsequently. Another problem is that the mechanical anchoring devices sometimes become jammed or broken and cannot be withdrawn, so that removal is prevented.

Recently, a design has been made in which the anchoring arrangement includes an element having longitudinally extending ribs, which are pressed outwardly by fluid pressure internally exerted against `a diaphragm. In this design, the ribs frictionally grip the surface of the well casing rather than digging into the casing surface to hold in shear. While this has provided a substantial improvement over earlier practices, nevertheless, it is relatively expensive to manufacture and necessitates the inclusion of several accurately machined parts.

The present invention provides a simplified design in which a granular material is utilized as the anchoring medium. The granular material, which typically is sand, is forced outwardly to engage the casing in providing the retaining force. The sand may be received in an annular chamber around a mandrel and pressed against the casing by axially inward forces imposed by retaining elements at the opposite ends of the sand chamber. Also, a sleeve may be included around the inner wall of the sand chamber, permitting the application of fluid pressures to augment the force applied against the well casing. The sand provides a very large retaining force, so that the tool will be 3,422,897 Patented Jan. 21, 1969 ICC locked in place and will resist high loads tending to dislodge it. Nevertheless, it is easily removed when desired simply by releasing the sand and dumping it. As soon as the sand is released, there is no resistance to the movement of the tool. A plug utilizing this principle may be made very compact in length, and with few parts it still will provide a more than ample retaining force. This design allows the advantages of a permanent-type plug to be realized, with a tool that is, nevertheless, easily removable.

The present invention further provides a simple, but effective, locking means, whereby when the plug is set in a well bore in response to relative longitudinal movement of the body or mandrel and the external components supported on the body, the body and such external components will be effectively, but releasabley, locked in place so as to assure that the plug will hold in the well bore until it is desired that the plug be released. This locking means comprises a pair of concentric locking rings having opposing teeth thereon providing Wedge surfaces which act to force one of the locking rings into engagement with the body of the plug, and a third ring is disposed about the concentric locking rings and holds the same in a position at which the locking rings are in locking coengagement with one another and with the body.

An object of this invention is to provide an improved arrangement for holding a body in a well.

Another object of this invention is to provide a device which can be `anchored securely in place and will withstand extremely high loads.

A further object of this invention is to provide a plug or the like which is compact in dimension, simple to construct and operate and of low cost to manufacture.

Yet another object of this invention is to provide a plug having the advantages of a permanent-type plug, while at the same time being retrievable at will.

An additional object of this invention is to provide a locking arrangement for a well tool which will hold against extremely high forces, yet which can always be released without possibility of jamming or breakage and, when released, will Offer minimal resistance to movement.

These and other objects will become apparent from the following detailed description taken in connection with the accompanying drawing in which:

FIGURE l is a longitudinal sectional view of a tool embodying the invention, being lowered into a well casing;

FIGURE 2 is a view similar to FIGURE l, illustrating the tool after it has been anchored in place in the casing;

FIGURE 3 is an enlarged transverse sectional view taken along line 3-3 of FIGURE l, illustrating the arrangement for holding the chamber for the granular material in a foreshortened condition when the tool has been anchored;

FIGURE 4 is in an enlarged fragmentary longitudinal sectional view taken along line 4-4 of FIGURE 3;

FIGURE 5 is an enlarged transverse sectional view taken along line 5--5 of FIGURE l, illustrating the arrangement for admitting pressurized fluid into the zone inside the expansible sleeve;

FIGURE 6 is a longitudinal sectional view of a modiied form of the tool illustrated as anchored in the well;

FIGURE 7 is a transverse sectional View taken along line 7-7 of FIGURE 6;

FIGURE 8 is an enlarged fragmentary view of the lower portion of the tool of FIGURE 6;

FIGURE 9 is a fragmentary end elevational view of the annular member adjacent the seal at the lower portion of the tool;

FIGURE l0 is a longitudinal view of a further embodiment of the invention in which the provision for pressure augmentation of the anchoring force is omitted, showing the tool anchored in the Well; and

FIGURE ll is a transverse sectional view line 11-11 of FIGURE 10.

With reference to FIGURES l through 5, the invention is incorporated in a bridge plug 10, which is shown positioned within a well casing 11. The unit includes a mandrel 12, the lower end of which is threaded and receives a member 13. A stem 14 threads into the upper end of the member 13, and projects upwardly beyond the mandrel 12 as the device is being lowered into the casing in the view of FIGURE 1. Also at the upper end portion of the member 13 is an O-ring seal 15 to prevent fluid flow past the member 13 through the hollow interior of the mandrel.

The bottom end of the mandrel 12 flares outwardly and includes an annular flange 16 that extends to the bottom enlarged end portion 17 of an elastomeric sleeve 18 that circumscribes the mandrel. The upper end 19 of the sleeve 18 is similar to the bottom end 17, while the elongated portion 20 intermediate the ends has a thinner wall and is of smaller diameter. The effect is that of an annular recess in the outer surface of the sleeve 18, providing a chamber that is filled with a granular material 21, such as sand. Around the sand 21 is a cloth retaining sleeve 22 which serves merely to hold the sand within the space between the end sections 17 and 19 of the sleeve 18 as the tool is being run into the well. In other words, the cloth sleeve 22 will not allow the sand to flow out through the gap between the periphery of the tool and the wall of the casing, nor does it permit the sand to engage the casing wall prior to the time the tool is packed off in the well. The peripheral wall 23 of the sand, therefore, is along the open side of the annular chamber and of the same diameter as the shoulders defined by the elements 17 and 19 at the ends of the chamber. The cloth 22 is woven such that it will expand radially outwardly in response to an internal pressure exerted against it.

At the upper end of the sleeve 18 is a collar 24 having a flange portion 25 generally similar to the flange section 16 at the lower end of the mandrel 12. The collar 24 is slidable axially relative to the mandrel and is sealed with respect to the periphery of the mandrel by an O-ring 26 taken along The collar 24 also incorporates a means'for gripping the surface of the mandrel. This construction, which is best seen in the enlarged illustrations of FIGURES 3 and 4, includes a sleeve 27 integral with and extending from the upper end of the collar 24. The sleeve 27 is provided with teeth 28 on its inner periphery, which have upwardly facing inclined surfaces 28a and downwardly facing radial surfaces 28b. The inclined tooth portions 28a slope downwardly from the roots of the teeth 28 to the crests of the teeth. The sleeve 27 also is split, having longitudinally extending slots 29. In effect, it defines a plurality of fingers or segments.

On the inside of the sleeve portion 27 is an additional sleeve 30 which includes one longitudinal slot 31 through it, and which is provided with small teeth 32 on its inner wall which can be made to grip the outer surface of the mandrel 12. There are teeth 33 on the outer circumference of the sleeve 30 which mesh with the teeth 28 on the sleeve 27. The teeth 33 are similar in contour to the teeth 28, having surfaces 33a that face downwardly and incline upwardly and outwardly from the roots of the teeth to their crests. The other tooth surfaces 3311 extend radially.

A third sleeve 34 circumscribes the sleeve portion 27, extending above the two inner sleeves and including larger teeth 35 for engagement with a suitable auxiliary tool. Outside the lower portion of the sleeve 34 is a somewhat thicker sleeve 36, which at its bottom end is threaded to the collar 24. As the parts are assembled in this manner, the fingers defined by the slotted upper sleeve portion 27 of the collar 24 cannot be bent outwardly because of the sleeve 34 around its periphery backed up, in turn, by the outer sleeve 36.

Cil

At the bottom end of the mandrel there is an annular space 38 between the inner wall of the mandrel and the exterior of the central member 13. A passageway 39 provides communication from the interior of the well below the mandrel to the zone 38. A plurality of radial openings 40 extends between the upper part of the space 38 and a thin annular recess formed in the outer wall of the mandrel. At the radially inward part of the recess 41 is a split band 42 that extends over the openings 40. A similar recess 43 is provided above the recess 41, in which is another split annular band 44 covering radial openings 45. The latter apertures provide communication to the bore of the mandrel above the member 13.

In use of the tool illustrated in FIGURE l, it is lowered into the well casing 11 to the desired position where it is to be secured in place. At this time, a pull is exerted on the stem 14, while simultaneously a downward force is directed against the upper end 46 of the sleeve 36. The pull causes the lower end of the mandrel to exert an upward force on the bottom end portion 17 of the elastomeric sleeve 18. At the same time, the downward push on the sleeve 36 is transmitted to the collar 24, thereby pressing downwardly on the upper end 19 of the sleeve 18.

These forces cause the sleeve 36, the collar 24 and associated elements to slide axially toward the bottom end of the mandrel. This moves the upper end section 19 of the sleeve 18 downwardly away from its normal position toward the bottom end enlargement 17 of the sleeve. When this takes place, the chamber for the sand 21 becomes shorter. As a result, the chamber is reduced in volume inwardly of the circumferential surface 23 of the sand so that the sand 21 is forced outwardly. The enlarged ends 17 and 19` of the sleeve 18 compress the sand 21 from either end to cause the sand to move radially outwardly into engagement with the wall of the casing 11. The cloth sleeve 22 offers no appreciable resistance, releasing the sand for this outward movement in response to the forces against it.

The end sections 17 and 19 of the sleeve 18 are expanded radially as a result of the axial compression between the flanges 16 and 25 and the sand 21. Consequently, their outer circumferential surfaces are brought into firm engagement with the casing 11, and the sand 21 is trapped between the end portions of the sleeve 18, as seen in FIGURE 2. At the same time, the sand forced against the casing provides a strong frictional force to prevent axial movement of the tool. For wire line setting, pull is exerted against the stem 14 until it is fractured.

When the tool has been packed off to the position of FIGURE 2, the collar 24 and associated elements will remain shifted relative to the mandrel so that contracted length of the spa-ce for the sand 21 is maintained. This occurs because the mating teeth of the sleeves 27 and 30l impose a radially inward force component on the sleeve 3G that causes the small teeth 32 on the inner surface of the sleeve 30 to dig into the mandrel and hold the sleeve in place. The upward reaction on the collar 24 tends to cause the teeth 28 on the sleeve portion 27 to slip over the teeth 33 on the sleeve 30. Because of the downward and inward inclination of these teeth, this generates an inward force component that produces the locking effect. In other words, as the inclined surfaces 28a of the teeth 28 attempt to slide upwardly over the mating tooth surfaces 33a, an inwardly directed force F1. is produced that compresses the split sleeve 30` so that it grips the mandrel. The mating teeth act as cams in producing the inward reaction. The sleeve portion 27 cannot be expanded outwardly as a result of the forces on it because the sleeve 34 that circumscribes it will not permit such movement. Therefore, while the locking force is produced by the reaction of the teeth 28 and 33, these teeth cannot move axially past each other.

The teeth 28 and 33 lock the sleeve 30 against movement only in one direction, so that there is no interference with downward movement as the sand chamber is being compressed and the tool packed off. When the collar 24 is pushed downwardly, the radial tooth surfaces 28h engage the radial surfaces 33b of the teeth of the split sleeve 30, and pull the latter member along with the collar 24. There is no radial force component generated by the interengagement of these radial tooth surfaces.

The design of FIGURES 1-5 provides for the application of fluid pressure to augment the force against the sand resulting from the compression of the area in which the sand 21 is located. This fluid may come from either above or below the tool, From above, the pressurized fluid may pass through the apertures 45 and engage the undersurface of the split annular band 44. This lifts the band from over the apertures so that the fluid can enter the recess 43. This provides communication with the inside surfaces of the sleeve 181 at its central portion 20 so that the fluid can react through the sleeve and against the sand 21. The sleeve will be lifted outwardly from the surface of the mandrel generally as indicated in FIGURE 2, applying the uid pressure to the sand and causing it to bear Imore tightly against the casing. The fluid cannot escape from the area beneath the central portion 20 of the sleeve 18 because it cannot pass the annular band 42 to enter the openings 40. While the band 42 could be lifted easily by pressure from beneath it, it will be pressed firmly over the openings 40* by `fluid pressure within the annular area '41 so that it will not transmit fiuid from the space inside the sleeve 1-84 to the passageway 38.

The end sections 17 and 19 of the sleeve are pressed tightly against the surface of the mandrel and prevent escape of fluid around the sleeve.

0f course, the same principle applies in the event the pressurized fluid is received from below. When that occ-urs, the fluid is transmitted through the passageways 39 and 38, lifting the band 42 to enter the annular space 41 and communicate with the interior of the central portion 20 of the sleeve 18. The pressure is trapped within the space within the central portion of the sleeve because it cannot pass outwardly through the band 44 to enter the apertures 45. Therefore, the fluid pressure that is received by the plug, either from above or from below, is applied through the sleeve 18 to the sand 21.

As a result, the sand is pressed outwardly against the casing with an extremely high force. This granular material provides a secure locking force that will hold more firmly than virtually any other kind of anchoring arrangement. The particles of sand when under pressure will not flow or move relative to each other, but will provide a 'unitary mass that presses outwardly against the casing. The granular nature of the sand means that it tends to grip the wall of the casing securely, with each exposed grain presenting its own highly concentrated localized pressure area at the casing wall. Thus, the tool can be left in the place as long as desired without fear of its being dislodged under almost any conditions it may encounter. Once it has received fluid pressure from above or below, the pressure is trapped inside so that the retaining force is not dissipated.

The holding force is released quite simply merely by moving the sleeve 34 relative to the remainder of the plug. This is accomplished by engaging the exposed teeth 3S of the sleeve 34 and pulling the sleeve upwardly relative to the mandrel 12 and the sleeves 27, 30 and 36. When this is done, there no longer is any restraint in the radial direction imposed upon the split sleeve portion 27 of the collar 24. Consequently, there is nothing to preclude the interengaging teeth 28 and 33 of the sleeve 27 and inner sleeve 30 from `sliding relative to each other, bending the sleeve 27 as permitted by the multiple slots 29 in it. As the fingers defined by the Split sleeve portion 27 expand, all retaining force is lost. As a result, the force on the compacted sand 21 then can move the collar 24 upwardly on the mandrel toward its original position. The sand then dumps through the space around the periphery of the tool, and the anchoring force is entirely alleviated. This permits the tool to be removed from the well. The tool then is ready for reuse simply by introducing another quantity of sand into the space recessed in the outer wall of the sleeve 1S, which permits the operation to be repeated. Thus, while the device holds securely and indefinitely in place, it is especially easy to release and to use again. Alternative to the release described above, the pressure on the sand may be alleviated by cutting away the outer peripheral portions of the upper end portion 19 of the sleeve unit 18.

In the embodiment of FIGURES 6 and 7, the mandrel 47 threadably receives a central element 48 at its lower end, which is in turn connected to a stem 49 for packing off the tool, as described above. A seal 50 prevents leakage between the bore of the mandrel and the element 48. A ange 51 -at the lower end of the mandrel engages and receives one annular end portion 52 of an elastomeric sleeve 53. A thinner central portion 54 extends to the opposite end portion 55, which is similar to the section 52 and is engaged by the flange 56 of a collar 57 above the sleeve. As before, a granular material 58, such as sand, is received in the space between the annular end members and the central portion of the elastomeric sleeve 53.

In the arrangement of FIGURES 6 and 7, no cloth sleeve is shown around the open wall of the sand chamber as in the arrangement of FIGURES 1 through 5. The sand may be retained by other means which will release to allow the sand to move outwardly against the casing. This may be a binder that holds the sand particles together, at least at the outer circumferential surface, which will be fractured under pressure. The binder may be of suitable plastic or a light cement mixture with the sand that is readily broken as the force is applied. The material in the annular chamber, therefore, may be an integral mass when first associated with the mandrel, but will assume a particulate form under compression. As used in this application, granular material is intended to encompass such substances.

A lip 59 inclines both radially and axially inwardly at the upper end of the sleeve 53, while a similar lip 60 is provided at the lower end of the sleeve. These provide the effect of `check valves, permitting flow inwardly from the ends of the sleeve to the central portion of the mandrel beneath the sleeve. However, because of their inclined nature, the lips 59 and 60 trap uid within the space beneath the sleeve 53 and will not permit ow outwardly.

Inwardly of the lip 59 is a threaded ring 62 having a plurality of slots 63 in its upper end where it fits within the space defined by the lip 59 of the sleeve 53. This permits communication for fluid through the space 64 Vbetween the mandrel and the collar 57 through the detiectable lip 59, the slots 63 and along the interior of the ring 62. There are no 4threads on the mandrel to mesh with the threads of the ring 62, so that the threads on the ring serve only to provide a fluid passage to the interior of the elastomeric sleeve 53.

At the bottom end, fiuid ports 65 allow fiuid to enter by deflecting the lip 60, at which time it may pass a threaded ring 66, which is identical to the ring 62 (see FIGURE 8). Thus, the ring 66 includes slots 67 at its lower end adjacent the lip 60, through which the fluid may pass to the interior of the sleeve 53.

In order to facilitate the passage of fluid through the central part of the tool, and allow the fluid to contact the sleeve around its inner circumference, several longitudinal slots 68 are machined into the periphery of the mandrel. Thus, fluid received from above or below the plug illustrated in FIGURE 6 can enter the groove 68 and communicate with the inner wall of the central portion 54 of the sleeve 53. Again, therefore, the fiuid pressure may be utilized to help force the sand outwardly against the wall of the casing.

Prior to this time, of course, the tool is packed olf in a manner similar to -th-at of the previously described embodiment of FIGURES l through 5. Release of the tool may be accomplished in the `manner described in that embodiment, so that the retaining force is dissipated without diiculty and the tool can be shifted as desired.

In the arrangement of FIGURES `6 and 7, the end portions 52 and 55 of the sleeve 53 are provided with longitudinally extending grooves 70 `and 71 in their cylindrical outer surfaces. These grooves allow fluid that may surround the sand chamber or impregnate the sand S7 to escape when the sand is forced outwardly as its chamber Iis shortened. Thus, there will be no hydraulic lock that would prevent proper compression of the sand to force it firmly against the wall of the casing. Instead, as the uid is dissipated, it can pass through the slots 70 and 71 -to the exterior of the tool. The slots 70 and 71 communicate with the recessed zone in which the sand is received, but do not quite extend to the ends of the sections 52 and 55 of the sleeve. The fluid from within the sand can pass the remaining ungrooved periphery of the sleeve as the recess for the sand becomes shorter. However, once the sand is fully pressurized, the peripheries of the end sections 52 and 55 bear tightly against the casing to hold the sand within the central portion of the device and prevent fluid from moving past the exterior of the tool.

The grooves of the end sections 52 and I55 may be formed as well in the end portions 17 and 19 of the sleeve 18 of the embodiment of FIGURES 1 through 5 for assuring that `any excess Huid with the sand can be displaced.

The arrangement of FIGURES l and 1l is packed off in the well entirely by the exertion of a compression force on the sand and does not include a provision for augmenting the locking force through the admission of pressurized fluid. Hence, there is no sleeve in this design. This results in a tool lof greater length than before in obtaining an equivalent resistance to movement in the well.

Here, the plug includes a mandrel 73 having a central member 74 similar to the member 48 of the arrangement 0f FIGURE 6r. A collar 75 of elastomeric material is above the bottom ange 76 of the mandrel, while a similar elastomeric sealing element 77 is positioned 'beneath a collar 78 at the uppper portion of the tool. Granular material such as sand 79 is disposed around the mandrel in the space between the elastomeric collars 75 vand 77. There is no elastomeric sleeve interconnecting the elastomeric end members as in the embodiments of the invention described above.

A sleeve 81 is located along the inner surface of the lower part of the elastomeric collar 75, having an outwardly extending flange 82 that fits into a recess in the ange 76 of the mandrel 73. An identical sleeve 83, provided with a flange 84, is located at the upper elastomeric collar 77. The sleeves 81 and 83 are larger in diameter than the mandrel 73, so that there is a clearance along their inner peripheries.

Beneath the ange 82 of the sleeve 81 is an annular seal 85, while a similar seal 86 is disposed above the flange 84 of the upper sleeve 83. These seals have lip portions inclined toward the surface of the mandrel, and axially away from the region between the elastomeric collars 75 and 77. Hence, the seals 85 and 86 will deflect to allow flow outwardly of the region of the sand 79, but seal against the surface of the mandrel to prevent liuid flow inwardly. Communication to the exterior is completed at the bottom of the mandrel through ports 87 in the end of the mandrel, and at the top yby ports 88 in the collar 78.

When this tool is `being set, it is packed olf as before,

with the stem 89 being pulled as the collar 78 is pressed inwardly toward the bottom flange 76 of the mandrel. This moves elastomeric collars and 77 toward each other, tio in turn force the sand 79 outwardly against the wall of the casing. The inclined surfaces 90 and 91 of the collars 75 and 77 help the reaction with the sand compress the collars and expand them radially so that they seal against the casing. When this compression occurs, uid within the sand 79 may escape through the seals and 86. Thus, uid can pass through the clearance between the surface of the mandrel and the sleeve 83, deflecting the lip of the seal 86 to flow outwardly through the ports 88 at the top of the tool. Similarly, fluid may flow through the sleeve 81 past the seal 85 and outwardly through the ports 87 at the bottom of the tool. External pressures, however, will not enter to the area of the sand by virtue of the construction of the seals.

Fluid also can be dissipated through the longitudinal slots 92 and 93 formed in the periphery of the elastomeric collars 75 and 77. With two escape passageways for uid from the sand 79, there is complete assurance that there will be no hydraulic lock and that all excess fluid can escape from the center of the tool as it is packed olf.

Again, release is effected by suitably relieving the downward force on the collar 78 in a manner which may be similar to that in the arrangement of FIGURES l through 5.

The foregoing detailed description is to `be clearly understood as given by way of illustration and example only, the spirit and scope of this 'invention lbeing limited solely by the appended claims.

I claim:

1. A device for insertion and retention within a well comprising a 'body receivable in a well,

means on said body defining a chamber,

said chamber having open outer wall means,

a quantity of material which under pressure has a particulate form received in said chamber,

and means for forcing said material outwardly through said open outer Wall means for engaging and pressing said material against adjacent wall portions of a well into which said body has been inserted for frictionally engaging said wall portions and thereby holding said body relative to said well.

2. A device for insertion and retention in a well comprising a body,

means on said body delining an open outer-sided annular chamber,

a quantity of granular material in said chamber, means normally retaining said granular material in said chamber so that said granular material has a normal outer peripheral wall,

and means for reducing the volume of said chamber inwardly of said outer peripheral wall of Said granular material for forcing said granular material outwardly beyond said normal outer peripheral wall thereof for engagement with an adjacent surface of a well,

said retaining means releasing said granular material for said outward movement upon said reduction in volume of said chamber,

said means dening said chamber including means for holding said granular material to said body when said granular material is so forced outwardly so that said granular material through said engagement with said surface resists movement of said body in said well.

3. A device for providing a body retained in a well casing comprising a mandrel,

a duality of annular members circumscribing said mandrel in a spaced relationship with each other,

said members and mandrel defining a chamber around said mandral intermediate said members,

said chamber having an open outer wall means,

a quantity of granular material in said chamber,

means normally retaining said granular material in said chamber at said open outer wall means,

said retaining means being responsive to an outward force on said granular material for releasing said granular material and permitting outward movement thereof, and means for moving said annular members relatively toward each other so that said chamber is reduced in length,

whereby said granular material is forced outwardly through said outer wall means for frictional engagement with the wall of a -Well casing into which said mandrel has been inserted, said annular members including means for engaging said wall when said granular material is so forced outwardly for holding said granular material in said chamber.

4. A device as recited in claim 3 including in addition fluid transmitting means for said chamber for transmitting fluid to the exterior thereof when said annular members are so moved relatively toward each other.

5. A device as recited in claim 3 including means axially securing one of said annular members relative to said mandrel,

the other of said annular members being axially slidable relative to said mandrel for thereby permitting said annular members to be moved relatively toward each other, and including means for holding said other annular -member in a position to which it is moved toward said one annular member, said holding means including a first compressible sleeve means around said mandrel, a second expansible sleeve means movable with .said other annular member,

said first and second sleeve means having cam surface means in interengagement when said second sleeve means is unexpanded and substantially disengaged when said second sleeve means is expanded,

said cam surface means when in interengagement producing a radially inward force component on said rst sleeve means for compressing said rst sleeve means against said mandrel for resisting movement thereof relative to said mandrel as a result of an axial force on said second sleeve means tending to move said second sleeve means away from said one annular member, and expansion-preventing means for normally maintaining said second sleeve means unexpanded,

said expansion-preventing means being selectively releasable for permitting expansion of said expansible sleeve means and disengagement of said cam surface means for relieving said inward force on said compressible sleeve means so that said first and second sleeve means can move axially relative to said mandrel. 6. A device for insertion and retention in a well casing comprising a mandrel, a duality of spaced elastomeric members circumscribing said mandrel, an expansible sleeve circumscribing said mandrel intermediate said members,

said elastomeric members -being of larger diameter than said sleeve,

whereby said elastomeric members and said sleeve define an annular chamber having an open outer wall, a quantity of granular material in said chamber, means for moving said elastomeric members relatively toward each other for thereby axially shortening said annular chamber and forcing said granular material outwardly to engage a well casing in which said device is received, means for admitting pressurized fluid to the interior of said sleeve for thereby producing a force transmitted from said sleeve to said granular material for forcing said granular material against said Well casing, and means normally retaining said granular material within said annular chamber,

said retaining means being responsive to said force exerted on said granular material for releasing said granular material and permitting said granular material to move outwardly for said engagement with said casing. 7. A device for insertion and retention in a well casing comprising a tubular mandrel, a duality of annular elastomeric members circumscribing said mandrel,

said annular members in a normal position being axially spaced apart a predetermined distance,

an elastomeric sleeve circumscribing said mandrel intermediate said annular members,

said members being of greater diameter than the diameter of said sleeve so that said members and said sleeve dene an annular chamber having an open outer circumferential Wall,

a quantity of granular material substantially filling said annular chamber,

means for pushing said annular members relatively toward each other and holding said annular members relative to said mandrel at an axial position in which they are closer together than said normal position thereof,

-Whereby said annular chamber is reduced in length and said granular material is forced outwardly for engagement with the adjacent wall of a well casing,

means for introducing uid from within said casing through said mandrel to the interior of said sleeve for applying a uid pressure on the interior of said sleeve for forcing said granular material outwardly against said wall of said casing,

and means normally retaining said granular material in said chamber at said open outer circumferential wall thereof,

said retaining means being releasable in response to said force on said granular material for permitting said granular material to move outwardly and engage said wall of said casing.

8. A device as recited in claim 7 in which for said introduction of said uid through said mandrel to said sleeve said mandrel is provided with passage means communicating with the exterior of said mandrel above said annular members and below said annular members,

and including in addition check valve means for allowing entry of said nid to said space beneath said sleeve while preventing flow outwardly from said space.

9. A device as recited in claim 7 including in addition passage means in the outer circumferential portions of said annular members for permitting egress of uid from said chamber when said chamber is so reduced in length and said granular material is forced outwardly against said casing.

10. A device as recited in claim 9 in which each of said annular members presents a cylindrical outer circumferential portion for engagement with said well casing upon the compression of said annular members when said annular members are moved toward each other and said granular material is yforced outwardly against said casing,

said passage means of said annular members including a plurality of longitudinally extending grooves in saidV cylindrical portions of said members for allowing fluid to flow therethrough when said cylindrical portions are in said engagement with said well casing. 11. A plug device for a well comprising a tubular mandrel, means closing the bottom end of said mandrel,

said mandrel including a laterally outwardly projecting shoulder at the bottom portion thereof, a collar circumscribing said mandrel remote from said bottom end,

said collar including a laterally outwardly extending shoulder, an elastomeric sleeve intermediate said shoulders,

said sleeve including a radially thickened portion at either end,

said portions being in engagement with said shoulders, said sleeve having a radially thinner portion intermediate said end portions,

thereby to define an annular recess, a quantity of granular material in said annular recess, said collar being axially movable relative to said mandrel from a rst position remote from said shoulder of said mandrel to a second position relatively adjacent said shoulder of said mandrel,

for thereby reducing the length of said annular recess for forcing said granular material radially outwardly for engagement with an adjacent wall of a well casing, means associated with said collar for gripping said mandrel and locking said collar in said second position thereof, passage means providing communication between the inside of said intermediate portion of said sleeve and the exterior of said mandrel above and below said end portions of saidsleeve, check Valve means for permitting flow of fluid inwardly to said inside of said sleeve while precluding flow in the opposite direction, and means normally retaining said granular material in said recess,

said last-mentioned means including means responsive to outwardly directed forces on said granular material for releasing said granular material and allowing said granular material to move outwardly for engagement with said adjacent wall of said well casing. 12. A device as recited in claim 11 in which said passage means includes a first portion extending inwardly from said bottom 'end of saidmandrel, a first annular portion in the periphery of said mandrel, first radially directed opening means from said first portion to said recess, second radially directed openingmeans upwardly of said bottom end of said mandrel, said mandrel having an internal passage extending from the upper end of said mandrel to said second radially directed opening means, a second annular portion communicating with said second radially directed opening means, and in which said check valve means includes a member in either of said annular portions normally covering said radially directed opening means therein for preventing flow of fluid outwardly therethrough,

each of said members being displaceable in response to fluid pressure in the adjacent radially directed opening means for providing communication between said adjacent radially directed opening means and the one of said annular portions in which said member is received'.

13. A device as recited in claim 11 in which said passage means includes a first portion extending inwardly of said mandrel to the peripheral surface thereof adjacent said intermediate portion of said sleeve,

and a second portion extending from the upper end portion of said mandrel to said peripheral portion thereof,

and in which said check valve means includes a resilient lip integral with either of said end portions of said elastomeric sleeve,

said lips being inclined radially and axially inwardly relative to said sleeve to an inner surface adjacent the peripheral surface of said mandrel,

whereby said lips are deflectable to allow fluid flow inwardly but substantially preclude fluid flow outwardly from said peripheral portion of said mandrel.

14. A plug device for a well comprising a tubular mandrel,

said mandrel having a flange portion at the bottom end portion thereof,

means closing said bottomr end portion of said mandrel,

a rst resilient collar member circumscribing said mandrel adjacent said bottom end portion of said mandrel and engaging said flange portion,

a second resilient collar member circumscribing said mandrel upwardly of said first collar member,

an annular member ciroumscribing said mandrel above said second collar member.

said annular member having a flange portion engaging said second collar member,

means providing a passage from the exterior of said mandrel below said first collar member to the space exteriorly of said mandrel intermediate said collar members,

means providing a passage from the exterior of said mandrel above said second collar member to said space,

a check valve means in each of said passage means permitting flow outwardly from said space to above and below said collar members while precluding flow inwardly to said space,

a quantity of granular material in said space,

said annular member being movable axially relative to said mandrel for advancing said second collar member toward said first collar member from a first position remote from said first collar member to a second position relatively adjacent said first collar member,

thereby to shorten said space and force said granular material outwardly to the Wall of an adjacent well casing,

means for holding said annular member in said second position for maintaining said granular material so displaced outwardly,

and retaining means normally holding said granular material inwardly for precluding engagement thereof with said casing and retaining said granular material intermediate said collar members,

said retaining means being responsive to force applied to said granular material for releasing said granular material and permitting said outward movement thereof.

15. A device as recited in claim 14- n which each of said collar members has a radially and axially outwardly inclined surface engaged by said granular material,

said surfaces being adjacent said portion of said mandrel intermediate said collar members.

16. In combination with an elongated member, a device for selectively locking against movement relative to said member comprising a first sleeve means circumscribing said member, said rst sleeve means being compressible inwardly against the periphery of said member,

a second sleeve means around said first sleeve means,

said first and second sleeve means having interengaging cam surface means for preventing substantial movement of said second sleeve means relative to said first sleeve means and producing an inward component of force on said first sleeve -means for compressing said first sleeve means inwardly to grip said member upon the exertion of an axial force on said second sleeve means, said second sleeve means being expansible outwardly away from said member for substantially disengaging said cam surface means upon the exertion of an axial force on said second sleeve means,

and expansionpreventing means engaging said second sleeve means for preventing said outward expansion thereof so that such an axial force produces said inward force component to so compress said first sleeve means,

said expansion-preventing means being selectively releasable from said second sleeve means for allowing said expansion of said second sleeve means.

17. In combination with an elongated member, a device for selectively locking against movement axially of said member comprising a first split sleeve means circumscribing said member,

said first split sleeve means having tooth means on the exterior cirmumferential surface thereof,

said tooth means having surface portions inclined relative to the axis of said first sleeve means,

a second split sleeve means circumscribing said first sleeve means,

said second sleeve means having tooth means on the interior circumferential surface thereof,

said tooth means of said -second sleeve means including surface portions inclined relative to the axis of said second sleeve means and meshing with said tooth means of said first sleeve means,

said `second sleeve means being outwardly expansible relative to said first sleeve means for permitting said tooth means of said second sleeve means to move over said tooth means of said first sleeve means and -said second sleeve means to move axially relative to said first sleeve means upon the imposition of an axial force on said second sleeve means,

and expansion-preventing means normally preventing said expansion of said `second lsleeve means so that an axial force on said second sleeve means reacting through said inclined surface portions of said tooth means produces an inward force component for compressing said first sleeve means inwardly to grip said elongated member,

said expansion-preventing means being selectively releasable from said second sleeve means for permitting said outward expansion of said second sleeve means.

18. A device as recited in claim 17 in which said tooth means of said first and second sleeve means include substantially radially extending interengageable tooth portions for allowing said second sleeve means to move said first sleeve means relative to said elongated member in one direction upon interengagement of said substantially radially extending portions without producing an inwardly directed force component on said first sleeve means.

19. A device as recited in claim 17 in which said expansion-preventing means includes a substantially inexpansible third sleeve means circumscribing said second sleeve means,

said third sleeve means having an inner surface in engagement with said second sleeve means, said third sleeve means being slidable axially relative to said second sleeve means to a position of disengagement of said inner surface from said second sleeve means so that said second sleeve means is permited to expand.

Z0. In a bridge plug adapted to be set in a well casing: an elongated body, anchor means on said body expansible into anchoring engagement with the well casing, packing means expansible into sealing engagement with said well casing, a first member connected to said body for moving said body in one direction, a second member for effecting 20 expansion of said anchor means and said packing means lupon movement of said body in said one direction, locking means for releasably holding said body and said second member in positions with said anchor means and said packing means expanded, said locking -means including a pair of lsplit locking rings concentric with said body and expansible and contractible relative to one another, one of said locking rings shiftably engaging said body for allowing movement of said body in said one direction, the other of said locking rings being connected to said second member, said locking rings Shaving confronting wedge surfaces for forcing said one of said locking rings into engagement with said body to prevent movement of said body relative to said second lmember in the other direction, and a third ring movable between a first position engaged with said other locking ring and a second position releasing said other locking ring for allowing disengagement of said wedge surfaces.

21. A bridge plug as defined in claim 20, wherein said third ring is shiftably carried by said second member and includes .means engageable by an auxiliary tool for moving said (third ring to said second position.

22. In a well packer for packing ofi a well bore, a body adapted to be disposed in said bore, said body having normally retracted packing means expansible into sealing engagement with the well bore, and normally retracted anchor means expansible into anchoring engagement with the well bore, lche improvement wherein said anchor means comprises .an annular body of discrete particulate material, and including means at opposite ends of said body of particulate material for axially moving the same to effect outward expansion thereof.

123. A well packer as defined in claim 22, wherein said means at opposite ends of said body of particulate material includes said packing means, and including a first annular member carried by said body for longitudinal movement therewith, a second annular member slid-able relative to said body to effect expansion of said packing means and said anchor means, and releasable lock means for holding said body and said second annular member in positions with said packing means and said anchor means expanded.

References Cited UNITED STATES PATENTS 1,503,693 8/1924 McLean 166-206 X 1,652,562 12/1927 Day 166--192 X 2,173,903 9/1939 Halliburton 166--117 2,451,762 10/1948 Millikan 166--187 X 3,000,443 9/1961 Thompson 166-135 3,085,627 4/1963 Sodich 166--212 X DAVID H. BROWN, Primary Examiner.

U.S. Cl. X.R. 

